A storage array is a storage system which includes multiple storage drives. A storage system is attached to a computer system to provide storage for the computer system. Direct attached storage (DAS) is a storage system directly attached to a computer system, without a storage network in between the computer system and the storage system. Network attached storage (NAS) is a file-level storage system connected to a computer network which provides storage access to heterogeneous network clients. A storage area network (SAN) is an architecture to attach remote storage devices (such as disk arrays, tape libraries, and optical jukeboxes) in such a way to computer systems that the storage devices appear as locally attached.